The Department of Justice on Wednesday joined a lawsuit against Gallup after a whistle-blower alleged the organization overcharged the government for polling services.

The whistle-blower lawsuit, filed by a former Gallup employee, claims the firm gave the government inflated estimates for polling services and made federal agencies pay far more than what Gallup’s internal estimates called for, the DOJ announced.

“Contractors must understand that it is unlawful to use inflated estimates to obtain higher contract prices,” Stuart Delery, Acting Assistant Attorney General for the Justice Department’s Civil Division, said in a statement. “The decision to join this civil lawsuit underscores the commitment of the Department of Justice to recover federal funds that are unlawfully claimed.”

The lawsuit alleges the Gallup Organization violated the False Claims Act, under which the government can recover three times its losses, as well as civil penalties. The ex-Gallup employee turned whistle-blower claims the firm gave the U.S. Mint, the State Department and other federal agencies contracts with inflated estimates for how many hours it would take to provide polling services, and that the government paid Gallup based on those false numbers.

“Contractors who do business with the federal government must honor their obligations to provide honest services and products,” U.S. Attorney Ronald Machen Jr., said. “Working with relators and federal investigators, we will do all that we can to act against those who illegitimately bill the American taxpayers.”

The whistle-blower’s complaint alleges that while Gallup’s employees report accurate estimates of hours required to complete polling services, the firm then inflates those estimates to the government.

“The result is that while the Government overpays for Gallup’s services in the form of a falsely inflated contract price, Gallup employees earn larger bonuses because the gross margin on the contract grows in proportion to both the larger contract price and lower actual costs,” the complaint states.

Under two separate counts, the complaint claims the U.S. has “suffered actual damages of at least $10 million.”

The Justice Department has not filed its own complaint yet.

William Kruse, associate counsel with Gallup, said the polling firm finds the lawsuit “shocking.”

“We’re just shocked the Department of Justice would pursue this kind of a meritless claim,” he told POLITICO.

The government, Kruse said, “had a chance to vet these prices in advance and now, years later, they want to come back and say they should have been charged less for them.”

“We look forward to the Justice Department explaining itself in court,” he added.